i would remanufacture it. see if you can find a good shop in your area. being from texas myself and seeing thats where you are, you should have plenty of options and places that specialize in trucks. i know an engine may be just an engine but, i feel better having somebody who is into trucks working on mine. rather than say a shop that specializes in in rice burners but will pretty much do anything that rolls in.
as mentioned in other threads and from actual quotes i've had in the last few months- it will probably run around $2500 ish. this would include removal of the engine, a quality job (resurfacing, overboring, etc) and reinstallation of your engine. and it would also include any new engine parts you want to bring along to have them installed while they have it out. you could get it for less $$$ but that means they're pretty much going to just reinstall all your old EXTERNAL parts like the starter, alternator, etc. etc. so while it's out you may as well make it lke new and gather the parts so that would bring your estimate right around the $2500 range. a few hundred or so more if you upgrade to say a heavy duty starter and alternator or hi-per ignition parts. if you really want to blow it out performance wise- which is up to you- expect to pay more. weigh the costs vs. your needs before you do that though.
best thing to do is what i like to do. start picking up those parts, a starter, alternator, water pump, hoses, wires and plugs all those "little" things etc. unless you've already replaced them very recently of course and have them ready to go when you take it in for the rebuild. most shops i've talked to here will work within a budget. so lets say you don't want to go over $3000.
i would definitely and i think a lot of other members here would agree- stay away from a crate engine. members can confirm some of the nightmares. if you really insist on swapping to a bigger engine i would take it to a reputable place and see if they can make a recommendation.
it's good that you're taking your time rather than rushing into it. because it may be more expensive in the short term but, way more worth it in the long run. if your engine now is running semi reliably you can aways tune it up get her (or him -LOL) reliable as possible and drive it until it's time.
good luck.